babel.prep.corpus.MultipleXMLLangFileOutputFormat.java Source code

Introduction

Here is the source code for babel.prep.corpus.MultipleXMLLangFileOutputFormat.java

Source

/**
 * This file is licensed to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package babel.prep.corpus;

import java.io.IOException;

import javax.xml.stream.XMLStreamException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.lib.MultipleOutputFormat;
import org.apache.hadoop.util.Progressable;

import babel.content.pages.Page;

import babel.util.language.Language;
import babel.util.persistence.XMLObjectWriter;

/** 
 * Generates multiple XML files each containing pages in a single nalguage.
 */
class MultipleXMLLangFileOutputFormat extends MultipleOutputFormat<Text, Page> {
    static final Log LOG = LogFactory.getLog(MultipleXMLLangFileOutputFormat.class);

    protected String generateFileNameForKeyValue(Text key, Page page, String name) {
        Language lang = page.getLanguage();
        String strLang = (lang == null) ? "none" : lang.toString();

        if (LOG.isInfoEnabled()) {
            LOG.info("Language " + strLang + " for page " + page.pageURL());
        }

        CorpusGenerator.Stats.incLangPageCount(strLang);

        return strLang + "." + super.generateFileNameForKeyValue(key, page, name);
    }

    public RecordWriter<Text, Page> getBaseRecordWriter(final FileSystem fs, JobConf job, String name,
            final Progressable progress) throws IOException {
        final Path dumpFile = new Path(FileOutputFormat.getOutputPath(job), name);

        // Get the old copy out of the way
        if (fs.exists(dumpFile))
            fs.delete(dumpFile, true);

        final XMLObjectWriter xmlWriter;

        try {
            xmlWriter = new XMLObjectWriter(fs.create(dumpFile), false);
        } catch (Exception e) {
            throw new RuntimeException("Failed to instantiate XMLObjectWriter.");
        }

        return new RecordWriter<Text, Page>() {
            public synchronized void write(Text key, Page page) throws IOException {
                try {
                    xmlWriter.write(page);
                } catch (XMLStreamException e) {
                    throw new RuntimeException("Error writing page XML.");
                }
            }

            public synchronized void close(Reporter reporter) throws IOException {
                try {
                    xmlWriter.close();
                } catch (XMLStreamException e) {
                    throw new RuntimeException("Error closing XMLObjectWriter.");
                }
            }
        };
    }
}